just bought TP41 (4 ohm > 25w) yesterday using with micropod also 4 ohm
sound volume using between 9 - 12 o'clock, if over 2 o'clock the sound already no good
T amp over 80% efficiency, so not really hot at all
Class T amp 15W@4ohm > 7.5w@8ohm
what size of your speaker?